AuthorTopic: HR monitor problem (Read 62601 times)

The first impression was very positive, because it was the first time, that the measurementdidn't start at a value of >200 when I put the belt on. Instead it was about 80, which is mynormal HR value. During the first meters of running the value slowly increased, which is alsothe expected result. But then after a short time the value again went against 200 and above. This repeated several times.

I think the processing of HR values has improved: The valuesstart with a normal value, the curve is smoother - however, there are still wrong values.They are just filtered and smoothened. I think, it would be better to eliminate the source of the problem, instead of filtering and building average values. Of course it will be possibleto filter all and everything away by software, but finally this has nothing to do with your hart rate.

Right, I've waited for a long time before posting here - wanted to make sure I was going to post something accurate.

I've owned 3 different GH-625M units, all with different HR bands. My first unit was totally useless when it came to HR readings, often just not picking up a signal, or just reporting heart rates of 180bpm's or more for long periods of time. Because in Europe return policies are fairly liberal, I just took it to the shop and asked for a new one.

The second unit had basically the same problem - totally innacurate HR readings. I thought perhaps I just wasn't wearing it right, and tried different ways to put the band on - front of my chest, the back, on the side - upside down, with a t-shirt, without a t-shirt, etc, etc, etc. Basically it made no difference, HR readings just fluctuated to the point of making readings useless (we are not talking spikes, we are talking stretches of minutes at a time when HR readings were just plain wrong).

I then traded the unit for a third one - same problem. No difference whatsoever. I then started trying various techniques to try and improve the reading - wetting the HR band, spitting on it, various conductive liquids... nothing made a difference. HR readings were just too unstable, which suggests this is a fundamental design flaw - not just a fluke with a few HR bands.

I finaly decided to try the current beta firmware (3.1) together with rinsing the band thouroughly prior to each use - I hoped this would make a difference, but alas, it hasn't. Sure, now I get stable readings - but they are just the wrong stable readings - there is no way that after 10 minutes of cycling my heart rate goes up to 180bpm and stays there for 30 minutes, after which it goes down slowly to 150, and 30 minutes after I stop cycling that it goes up to 180bpm again!

Basically, I have decided to give up on the GH-625M and will be getting a different watch. If some kind soul can point me to somewhere in Europe where I can get a compatible, functional HR band then I will stick to it - but HR readings are fundamental for my training, and I am not going to give up on that functionality regardless of how well the other functions work.

I also tested Firmware beta 3.1 (F-GGH-2A-0903021). Although there are no unphysiological peaks (like > 210) and also no stationary parts in the heart rate curve, there are definetly phases of wrong measurement - or better say: wrong manipulations/recalculations of the measurements... It is like nunol said. In my case, I did a slow downhill run in the beginning of the training (usually this gives me a HR of about 120) and the watch steadily went up to 175 and - after a short drop to the values I would have expected - even went up to 185 for several minutes... after that the values seemed to be better for a longer period, but in the end of the run the unrealistic values apeared again...

This is realy tragic for me, since the HR was no problem in my case and perhaps many others using other belts - see my posts above. Now the calory sum problem seems fixed, but the HR becomes a new, even worse problem for me.Would it be possible to write a firmware with the calory and UTM problems fixed, but without the new harsh filtering (like a combination of F-GGH-2A-0903021 (HR) and F-GGH-2A-0905191 (calory and UTM)?

Else I see no other solution as to turn back to F-GGH-2A-0903021 and forget the calory calculation and UTM values of the watch since this is done even better by ST anyway.

greetings

Skeptisch

P.S. I was surprised that my costum values and settings and also the activities were still on the watch after FW update. How is this possible? I thought the whole memory will be ereased (and the watch also showed this message while updating)

Right, I've waited for a long time before posting here - wanted to make sure I was going to post something accurate.

I've owned 3 different GH-625M units, all with different HR bands. My first unit was totally useless when it came to HR readings, often just not picking up a signal, or just reporting heart rates of 180bpm's or more for long periods of time. Because in Europe return policies are fairly liberal, I just took it to the shop and asked for a new one.

The second unit had basically the same problem - totally innacurate HR readings. I thought perhaps I just wasn't wearing it right, and tried different ways to put the band on - front of my chest, the back, on the side - upside down, with a t-shirt, without a t-shirt, etc, etc, etc. Basically it made no difference, HR readings just fluctuated to the point of making readings useless (we are not talking spikes, we are talking stretches of minutes at a time when HR readings were just plain wrong).

I then traded the unit for a third one - same problem. No difference whatsoever. I then started trying various techniques to try and improve the reading - wetting the HR band, spitting on it, various conductive liquids... nothing made a difference. HR readings were just too unstable, which suggests this is a fundamental design flaw - not just a fluke with a few HR bands.

I finaly decided to try the current beta firmware (3.1) together with rinsing the band thouroughly prior to each use - I hoped this would make a difference, but alas, it hasn't. Sure, now I get stable readings - but they are just the wrong stable readings - there is no way that after 10 minutes of cycling my heart rate goes up to 180bpm and stays there for 30 minutes, after which it goes down slowly to 150, and 30 minutes after I stop cycling that it goes up to 180bpm again!

Basically, I have decided to give up on the GH-625M and will be getting a different watch. If some kind soul can point me to somewhere in Europe where I can get a compatible, functional HR band then I will stick to it - but HR readings are fundamental for my training, and I am not going to give up on that functionality regardless of how well the other functions work.

Best Regards.

--Nuno

Dear Nuno

Thanks for your using on GH-625 and provding the information.To find the cause, could you send me log file with FW 3.1 and series number of watch? We are wondering the wrong reading came from noise or calculation or belt.

Our belt is compatible with Echowell belt as 5KHz analog modulation without coded. And we have resourcing another belt because we found some quality problem of the current belts recently.

If the problem came from belt, we will arrange the new one belt to you soon.

I also tested Firmware beta 3.1 (F-GGH-2A-0903021). Although there are no unphysiological peaks (like > 210) and also no stationary parts in the heart rate curve, there are definetly phases of wrong measurement - or better say: wrong manipulations/recalculations of the measurements... It is like nunol said. In my case, I did a slow downhill run in the beginning of the training (usually this gives me a HR of about 120) and the watch steadily went up to 175 and - after a short drop to the values I would have expected - even went up to 185 for several minutes... after that the values seemed to be better for a longer period, but in the end of the run the unrealistic values apeared again...

This is realy tragic for me, since the HR was no problem in my case and perhaps many others using other belts - see my posts above. Now the calory sum problem seems fixed, but the HR becomes a new, even worse problem for me.Would it be possible to write a firmware with the calory and UTM problems fixed, but without the new harsh filtering (like a combination of F-GGH-2A-0903021 (HR) and F-GGH-2A-0905191 (calory and UTM)?

Else I see no other solution as to turn back to F-GGH-2A-0903021 and forget the calory calculation and UTM values of the watch since this is done even better by ST anyway.

greetings

Skeptisch

P.S. I was surprised that my costum values and settings and also the activities were still on the watch after FW update. How is this possible? I thought the whole memory will be ereased (and the watch also showed this message while updating)

Hello Skeptisch

Thanks for your information and testing. Could you send me the log file for check?We are eager to figure out the problem and confirm what happen before back to beta 1 on because the FW3.1 is just little different to beta 1 which with filtering on the abnormal of interval of HR pluse.

Thanks for your using on GH-625 and provding the information.To find the cause, could you send me log file with FW 3.1 and series number of watch? We are wondering the wrong reading came from noise or calculation or belt.

Our belt is compatible with Echowell belt as 5KHz analog modulation without coded. And we have resourcing another belt because we found some quality problem of the current belts recently.

If the problem came from belt, we will arrange the new one belt to you soon.

Sincerely,

Geoffrey

Sincerely,

Geoffrey

Geoffrey, I will send you a log file as soon as I can. If you can send me a new belt that works, it would be the solution to my problem. I quite like all the other features of the 625m, it is just the HR band that seems to let an otherwise good product down.

I have tested beta3.1. When i put on the belt and switched on the watch the diplayed hr values were about 180. So i cleaned the belt and tried again. Very high values again. I turned off the watch, switched it on again and waited several minutes, everytime the displayed values were different, but all far to high. I didn't test the watch with hr while running, because it makes no sense, as long as the values are not correct after switching on. I still think it is the belt which does not work properly. I was searching for this Echowell belt. It is axactly the same, but with another label. So there is no hope that it will be a solution.

Geoffrey: How to get the new type belt, you mentioned before??

I need exact heartrate measurements for my training. Until now i have spent much time in testing new FW which does not solve the problems. The situation is not acceptable. If there is no hope to solve the problem in a short time, I will be forced to search for another watch.

Are you really shure to solve the heartrate problems by a software hack? ...In my experience such problems can only be solved by an improved hardware design. Hopefully it will suffice to take another belt. If the problems are caused by the receiver in the watch, I fear there is no chance for an improvement. I can't imagine of a filter function which can separate between a real rise of the heartrate and and a rise caused by a bad signal.Dont't get me wrong: I really hope you are able to find a software solution very soon. A exact display of my heartrate is very important in my preparation for the next competitions. At the moment the situation is sad. So I need a solution urgently.

I'm an engineer, working in software development for highly reliable industrial automation systemsand I can tell you: If the hardware isn't able to provide correct values, the software will not be ableto "guess" correct results !

Like snow_freak said, for me it is also important to have a correct heart rate measurement for mytraining and I don't want to have a manipulated, smooth looking HR curve. This is not the goal !I want to see my heart rate values ! And when the pulse rises suddenly, I want to see that !I don't want it to be filtered (or smoothened).

As a summary, I suggest to remove filtering/smoothing of HRM or to use it veeeery carefully (filtering of one or two value's outside a wide range around "normal" might be okay) orallow filtering /smoothing to be enabled/disabled by user or

if you are sure, that the problems are caused by the belt, provide a new belt for forum members,having problems with HRM. (of course, in this case disabling of filtering/smoothing is also required !).

With some additional, minor modifications or optimizations, I would be almost satisfied with the other functions (especially GPS/navigation), but HRM is a fundamental function for me and if it doesn't work, it will make thecomplete watch useless.

I have tested the watch with beta-firmware 3.1 last week wiht my Polar-belt T61 coded parallel with my Polar S810i watch. The max. HR and the AVG HR were exept one time on both watches the same or rather +/- 1 beat. Only one time of six times the displayed heartrate on the GS-watch stays at 50 - 60 beats all the time . After cleaning the belt with liquid soap, the shown heartrate was the same than on the Polar watch .

I ask myself why the Polar watch didn´t have the problem with the heartrate. The signal which comes from the same belt must be well enough to detect (or calculate) the right heartrate. So it seems the reason of the problem is the reveiver. Only to use 2,4 GHz technology won´t solve the problem.

I think smoothing is not the right way. What about working on the signal-to noise ratio? Maybe a band-pass-filter can help to get a better s/n-ratio. Or think about the calculatuion of the heartrate. Do you use fast-fourier-transformation or a simple division 60sec/beat-to-beat time?

Hello, bought this sporttester cuz old one (pretty reliable) was stolen Belt kept at home so I have 2 pcs now. Old belt make some noise when heart beats. Tested: Heart beats about 80 bpm, watches shows 200+. THIS IS DAMNED ANNOYING. Using only this feature and it doesn't work. Another wierd working thing is cumulate+ and -. It counts only 30,60,90 etc meters? Where the $^$%%$^ is problem? This watches has GPS. Old one counts alt from atmospheric pressure and it counted 1 meter+! Is possible to release some WORKING firmware (at least HR)? I use it every day for training. Thank you 4 answer.

I have tested beta3.1. When i put on the belt and switched on the watch the diplayed hr values were about 180. So i cleaned the belt and tried again. Very high values again. I turned off the watch, switched it on again and waited several minutes, everytime the displayed values were different, but all far to high. I didn't test the watch with hr while running, because it makes no sense, as long as the values are not correct after switching on. I still think it is the belt which does not work properly. I was searching for this Echowell belt. It is axactly the same, but with another label. So there is no hope that it will be a solution.

Geoffrey: How to get the new type belt, you mentioned before??

I need exact heartrate measurements for my training. Until now i have spent much time in testing new FW which does not solve the problems. The situation is not acceptable. If there is no hope to solve the problem in a short time, I will be forced to search for another watch.

Regards

Dear Snow_Freak

Thanks for your kind support and testing.For the new belt, you can send request to me directly, I will discuss with our team on this case.

I have tested the watch with beta-firmware 3.1 last week wiht my Polar-belt T61 coded parallel with my Polar S810i watch. The max. HR and the AVG HR were exept one time on both watches the same or rather +/- 1 beat. Only one time of six times the displayed heartrate on the GS-watch stays at 50 - 60 beats all the time . After cleaning the belt with liquid soap, the shown heartrate was the same than on the Polar watch .

I ask myself why the Polar watch didn´t have the problem with the heartrate. The signal which comes from the same belt must be well enough to detect (or calculate) the right heartrate. So it seems the reason of the problem is the reveiver. Only to use 2,4 GHz technology won´t solve the problem.

I think smoothing is not the right way. What about working on the signal-to noise ratio? Maybe a band-pass-filter can help to get a better s/n-ratio. Or think about the calculatuion of the heartrate. Do you use fast-fourier-transformation or a simple division 60sec/beat-to-beat time?

I wish good luck in engenieering!

Longjog

Hello LongJog

Thanks providing the useful comments!! You like work in communication system field!!We will try to buy one from Polar belt, but the T61 coded belt seems be phased out...As I know, we have checked the C/N on GH-615 and HR Watch last year, they are 2.4 and 2.8 separately.That means GH-615 (not GH-625) is little weaker against environment noise than watch, because GH-615 embedded too many components which generate noise inside (battery, GPS, charger...).

There are two topics can be do:1. Reduce gain, but that means reduce noise energy as well as impact distance but with the same C/N.2. Try to improve C/N but keep the same gain.

But I don't know the 10 times different is coming from carrier of belt or coded or environment noise...

We will go further investigation includes 625, will feed back all valuable members soon.